thermal: ti-soc-thermal: Fix ti_thermal_unregister_cpu_cooling NULL pointer on unload
diff mbox

Message ID 20171016210714.16080-1-tony@atomide.com
State Accepted
Delegated to: Eduardo Valentin
Headers show

Commit Message

Tony Lindgren Oct. 16, 2017, 9:07 p.m. UTC
While debugging some PM issues and trying to remove all the loaded modules, I ran
across the following when unloading ti-soc-thermal:

Unable to handle kernel NULL pointer dereference at virtual address 000000b4
...
[<c08db340>] (kobject_put) from [<bf28954c>] (ti_thermal_unregister_cpu_cooling+0x20/0x28 [ti_soc_thermal])
[<bf28954c>] (ti_thermal_unregister_cpu_cooling [ti_soc_thermal]) from [<bf287c88>] (ti_bandgap_remove+0x3c/0x104 [ti_soc_thermal])
[<bf287c88>] (ti_bandgap_remove [ti_soc_thermal]) from [<c0610d48>] (platform_drv_remove+0x24/0x3c)
[<c0610d48>] (platform_drv_remove) from [<c060f114>] (device_release_driver_internal+0x160/0x208)
[<c060f114>] (device_release_driver_internal) from [<c060f200>] (driver_detach+0x38/0x6c)
[<c060f200>] (driver_detach) from [<c060e2d4>] (bus_remove_driver+0x4c/0xa0)
[<c060e2d4>] (bus_remove_driver) from [<c01f2370>] (SyS_delete_module+0x168/0x238)
[<c01f2370>] (SyS_delete_module) from [<c0108240>] (ret_fast_syscall+0x0/0x28)

Cc: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

J, KEERTHY Oct. 18, 2017, 3:49 a.m. UTC | #1
On Tuesday 17 October 2017 02:37 AM, Tony Lindgren wrote:
> While debugging some PM issues and trying to remove all the loaded modules, I ran
> across the following when unloading ti-soc-thermal:
> 
> Unable to handle kernel NULL pointer dereference at virtual address 000000b4
> ...
> [<c08db340>] (kobject_put) from [<bf28954c>] (ti_thermal_unregister_cpu_cooling+0x20/0x28 [ti_soc_thermal])
> [<bf28954c>] (ti_thermal_unregister_cpu_cooling [ti_soc_thermal]) from [<bf287c88>] (ti_bandgap_remove+0x3c/0x104 [ti_soc_thermal])
> [<bf287c88>] (ti_bandgap_remove [ti_soc_thermal]) from [<c0610d48>] (platform_drv_remove+0x24/0x3c)
> [<c0610d48>] (platform_drv_remove) from [<c060f114>] (device_release_driver_internal+0x160/0x208)
> [<c060f114>] (device_release_driver_internal) from [<c060f200>] (driver_detach+0x38/0x6c)
> [<c060f200>] (driver_detach) from [<c060e2d4>] (bus_remove_driver+0x4c/0xa0)
> [<c060e2d4>] (bus_remove_driver) from [<c01f2370>] (SyS_delete_module+0x168/0x238)
> [<c01f2370>] (SyS_delete_module) from [<c0108240>] (ret_fast_syscall+0x0/0x28)

Acked-by: Keerthy <j-keerthy@ti.com>

> 
> Cc: Keerthy <j-keerthy@ti.com>
> Signed-off-by: Tony Lindgren <tony@atomide.com>
> ---
>  drivers/thermal/ti-soc-thermal/ti-thermal-common.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> --- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> +++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
> @@ -278,7 +278,8 @@ int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
>  
>  	if (data) {
>  		cpufreq_cooling_unregister(data->cool_dev);
> -		cpufreq_cpu_put(data->policy);
> +		if (data->policy)
> +			cpufreq_cpu_put(data->policy);
>  	}
>  
>  	return 0;
>

Patch
diff mbox

diff --git a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
--- a/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
+++ b/drivers/thermal/ti-soc-thermal/ti-thermal-common.c
@@ -278,7 +278,8 @@  int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id)
 
 	if (data) {
 		cpufreq_cooling_unregister(data->cool_dev);
-		cpufreq_cpu_put(data->policy);
+		if (data->policy)
+			cpufreq_cpu_put(data->policy);
 	}
 
 	return 0;